From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 91F25C433B4 for ; Tue, 20 Apr 2021 21:04:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 555A5613F3 for ; Tue, 20 Apr 2021 21:04:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234057AbhDTVEt (ORCPT ); Tue, 20 Apr 2021 17:04:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54634 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233764AbhDTVEs (ORCPT ); Tue, 20 Apr 2021 17:04:48 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A11B1C06174A for ; Tue, 20 Apr 2021 14:04:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Transfer-Encoding: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content-Description; bh=33cl6Q0zBO2WtxzleEbaqu15B/eG+p6M3SX4MVpiqrk=; b=SasqnyUO0VXDzwPWUIt5rvdpEA NxeOD1J70CXru5fNWRTpW5zS94z8jeiYR0tQsfUmDy1xzChACTzzVw3g2HxoNXPdXDRjySo/5ge1l ltRsw4IN776o2CZ3zxXETt/9D7rFhLkl7pWo8BClPzHSYNBAGgxmhyNw77H9V4Ev0u3dTy1C6Hseu BbrkpXL30b8cKuAjIIoM5Aivwl2vrUS+QG/cpSW62WbpCg72LbaEYQ1DWTfEcYIv0a/ev+D7sFmLh Jdhrlpt6cqxtnaavTwaEIh0dboLPTj3nwpFamH3+b+dXwrN73tP5hCUCu3cZoMBCFJ+zbZYATUTIB RRVnED1w==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lYxWq-00FeRZ-JH; Tue, 20 Apr 2021 21:03:39 +0000 Date: Tue, 20 Apr 2021 22:03:28 +0100 From: Matthew Wilcox To: Jeff Layton Cc: David Howells , linux-fsdevel@vger.kernel.org Subject: Re: [PATCH] mm/readahead: Handle ractl nr_pages being modified Message-ID: <20210420210328.GD3596236@casper.infradead.org> References: <20210420200116.3715790-1-willy@infradead.org> <3675c1d23577dded6ca97e0be78c153ce3401e10.camel@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <3675c1d23577dded6ca97e0be78c153ce3401e10.camel@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Tue, Apr 20, 2021 at 04:12:57PM -0400, Jeff Layton wrote: > > @@ -210,6 +208,7 @@ void page_cache_ra_unbounded(struct readahead_control *ractl, > >   * not worth getting one just for that. > >   */ > >   read_pages(ractl, &page_pool, true); > > + i = ractl->_index + ractl->_nr_pages - index; i = ractl->_index + ractl->_nr_pages - index - 1; > > @@ -223,6 +222,7 @@ void page_cache_ra_unbounded(struct readahead_control *ractl, > >   gfp_mask) < 0) { > >   put_page(page); > >   read_pages(ractl, &page_pool, true); > > + i = ractl->_index + ractl->_nr_pages - index; i = ractl->_index + ractl->_nr_pages - index - 1; > Thanks Willy, but I think this may not be quite right. A kernel with > this patch failed to boot for me: Silly off-by-one errors. xfstests running against xfs is up to generic/278 with the off-by-one fixed.